barbells: The larger weights (for power lifting in a weight training program) that include a long bar with weights added to each end. You need to use both hands to lift a barbell.

Bioelectrical Impedance Analysis (BIA): A method of measuring your body fat in which you lie on your back while a signal travels from an electrode on your foot to an electrode on your hand. The slower the signal, the more fat you have.

blood pressure: A measurement of how open your blood vessels are. Low numbers mean that your heart doesn’t have to work very hard to pump the blood through your blood vessels.

body composition: How much of your body is composed of fat and how much is composed of everything else. Your body composition is also called your body-fat percentage.

body mass index (BMI): A way of relating your height and weight to estimate how fat you are. You can use a simple formula to determine your BMI.

body sculpting: A non-aerobic, muscle-toning class, usually focused on core strength.

BOSU: A domed, flexible apparatus that helps to improve balance and can be used in a step aerobics exercise routine. BOSU is an acronym for Both Sides Utilized.